Such polarized magnetic systems find use for the magneto-magnetic storage of the end positions of the armature. For such magnetic systems, the permanent magnets must be disposed in the course of the flux of the yoke legs of the magnetic system in order to achieve a permanent magnetic holding force in the end position of the armature. Furthermore, an electric coil is required, which, when supplied with an appropriate current, produces an electromagnetic force, which opposes the respective holding force and brings about a movement of the armature into the other end position.
Polarized magnetic systems are known, for which an electric coil is disposed in a U-shaped yoke of a magnet, the armature being provided at its end, which is facing the bottom of the yoke, with an axis, which is held in a recess of a magnetically conductive metal plate that is disposed between the bottom of the yoke and the underside of the coil former. In the case of the known magnetic systems, the permanent magnet, which is required for producing the permanent magnetic force, is inserted between the one longitudinal leg of the U-shaped magnetic yoke and the leg, which is offset 90.degree. to the one pole leg, while the other pole leg is fastened, for example, without interpositioning of a permanent magnet, directly to the other longitudinal leg of the U-shaped yoke of the magnet. In the case of the known magnetic system, the individual parts of this magnetic system, including the coil former but with the exception of the armature that is moveable on the armature axis, are connected to one another and secured in position by adhesive bonds. For such a magnetic system, however, a plurality of individual parts is required, which additionally must be glued together after they are assembled mechanically. For the purpose of maintaining given mechanical values, particularly of the operating air gap, extensive and complicated devices are required, which guarantee these values after the gluing procedure, since, for practical purposes, a correction is no longer possible once the adhesive has cured.
A polarized magnetic system is disclosed in the German offenlegungsschrift 34 18 471. For this system, a holding frame, overlapping the outer sides of the yoke leg, is provided for mounting the individual parts of the system. The holding frame is provided with guiding mechanisms, with which it can be slipped onto the magnetic system so as to fit precisely. For this magnetic system, which on the whole is satisfactory, relatively expensive adjusting work is, however, always still required during the assembly. Moreover, the use of an additional holding frame increases the manufacturing costs.
It is therefore an object of the invention to provide a polarized, reversible magnet of the initially mentioned type, for which the number of individual parts required is reduced to a minimum, which can be assembled without expensive adjusting work and which can therefore be manufactured inexpensively and so as to be easy to install.
This objective is accomplished owing to the fact that the coil former can be pushed with positive engagement into the U-shaped yoke, the lower coil former flange being provided with integral moldings, which engage recesses in or at the bottom of the yoke, that the upper coil former flange is constructed in the form of a frame and has recesses, which are engaged by the upper ends of the yoke legs, and that the bent pole pieces and the permanent magnets can be pushed through openings in the upper coil former flange into the magnetic system, stops at the coil former flange limiting the depth of penetration of the pole pieces.
The advantages achieved with the invention consist, in particular, therein that the complete magnetic system consists of a few individual parts, which are easily assembled, the assembly being accomplished by a simple assembling of the individual parts. Appropriate stops to the insertion of the pole pieces guarantee that the specified working air gap of the magnetic system is always achieved accurately without having to carry out additional adjusting work or use sensing or measuring gauges or other aids.
An embodiment of the invention is shown in the drawings and is described in greater detail in the following.